共查询到20条相似文献,搜索用时 46 毫秒
1.
2.
3.
4.
《腐植酸》2015,(6)
为了探究腐植酸(HA)对褐鳟鱼鳃和肌肉在抵抗镉(Cd)中毒方面是否发挥积极作用,进行了组织病理学和生物化学方面的研究。试验中,褐鳟暴露在仅施加2 ppm镉,施加2 ppm镉加5 ppm腐植酸,仅施加5 ppm腐植酸的3种环境条件下,分别测定其鳃和肌肉组织的谷胱甘肽过氧化物酶(GPx)、超氧化物歧化酶(SOD)、丙二醛(MDA)水平。在含镉条件下,褐鳟组织中的GPx和SOD活性显著低于对照组(P0.05),而含镉环境中褐鳟组织的MDA并未升高(P0.05)。然而,腐植酸并未影响镉造成的生化伤害。镉对鱼鳃和肌肉组织造成明显的组织病理学变化,而在镉+腐植酸处理组中,肌肉组织病理学变化较小。这些结果表明,腐植酸可从组织病理学方面中和肌肉组织镉中毒。 相似文献
5.
6.
7.
《腐植酸》2001,(Z1)
·综述与评论·腐植酸深加工在农业领域的研究进展1(1)农药与腐植酸物质1(6)腐植酸形成的微生物学机理研究概况2(1)腐植酸的生物活性及其研究2(6)加强腐植酸化学的基础研究推动腐植酸工业的发展2(9)·试验研究·利用生化法制取类腐植酸物质的探讨1(9)也谈黄腐酸液体制剂的生产开发1(12)水稻应用腐植酸包裹型长效尿素效果研究1(14)黄宁素生物肥增产抗病机制研究1(17)蛋鸡、猪添喂腐植酸钙腐植酸钠效果试验l(19)西红柿喷叶面肥肥效试验总结l(23)寻甸褐煤腐植酸对Ni(11)的吸附性能试验2(11)药用腐植酸锌合成的研究2(15)腐植酸胶体稳定性及其对… 相似文献
8.
9.
采用Fe2O3-V2O5二元固体酸催化剂,对哈密风化煤通过水热法催化氧化工艺制备腐植酸。通过正交实验对催化氧化工艺条件进行了优化,并且采用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、热重分析(TGA)研究了Fe2O3-V2O5二元固体酸催化剂的微观结构及形貌。结果表明:在酸煤比2∶l(m L/g),反应温度100℃,反应时间0.5 h,催化剂Fe2O3-V2O5用量为2%时腐植酸产率可达73.6%,比碱溶酸析工艺处理的风化煤中腐植酸产率提高了9.6%,表明水热法催化氧化工艺能明显提高腐植酸的产率。微观结构分析表明,Fe2O3-V2O5二元固体酸催化剂结晶性较好,同时具有良好的分散性和热稳定性。 相似文献
10.
11.
12.
人类对腐植酸的研究,已有二百多年的历史了,在二百多年的历史中已积累了大量的丰富知识,使腐植酸类物质在人类的生产和科研活动中的许多领域越来越发挥着不可估量的作用,特别是在工业、农业、医学、涂料、化妆、和环保等行业中的作用将越来越突出。从五十年代以来,国内外对腐植酸研究颇为活跃,已经取得了可喜的成果。然而,就腐植酸的化学实体,生成机理,生物活性功能与结构而论,仍还有许多不明之处,而且,就已获得的大量知识而论,也有混乱或相互矛盾的情况,可以说腐植酸的化学现在处在未成熟的阶段,还没有建立起一个统一的科学体系,改革开放以来,腐植酸事业得到蓬勃的发展,取得了可喜的成绩,尤其是腐植酸应用研究不断拓宽,更令人振奋的是发现腐植酸能有效地预防控制恶性肿瘤的生长和扩散,可以想象腐植酸化学的发展将对人类的农业、工业、环保和医学产生重大的影响,相对于应用研究来讲,基础研究还是相对薄弱。本文想就基础研究薄弱的原因作一分析和讨论,以引起同行们的重视和社会的关注。如有不妥之处请同仁指正批评。 相似文献
13.
The acid-base properties of humic acids from the brown coal of the Aleksandriiskoe deposit (Ukraine) were investigated. The
possibility of determining COOH and OH groups in humic acid macromolecules by different experimental methods was analyzed.
It was found that the results of potentiometric titration depend on the method of titration (homogeneous or heterogeneous),
the concentration of humic substances in the system, and the time taken to establish an equilibrium value of pH in the titrate.
It was shown that the amount of accessible functional groups (COOH and OH) in humic acid macromolecules, which can be determined
by a potentiometric method, is greater in homogeneous titration and at low concentrations of humic substances in solution.
It was established that the total amount of acid groups determined by a barium method is higher than that measured with the
use of potentiometric titration. The concentration of carboxyl groups determined by an acetate method is much lower than the
results of potentiometric titration and the barium method. It was shown that the potentiometric titration of homogeneous systems
(sodium humate + HCl) is preferable in the analysis of the acid-base properties of humic acids. 相似文献
14.
The ultimate analyses, u.v-visible absorption spectra, fluorescence spectra and i.r. spectra of five humic acids have been studied. One was obtained commercially from peat, two from organic-rich soils, one from an estuary and one from a marine sediment. The u.v. spectra were used to compare average molecular weights which varied from 800 to 7000 and increased with the atomic ratio. Fluorescence appeared to be due to poly-nuclear aromatic structures. All the humic acids showed maximum excitation at 360 nm and developed maximum emission in the range 430–455 nm but the humic acids from sediments showed an additional emission maximum at ~410 nm. Fluorescence from the peat humic acid was broad and secondary emission was observed with a maximum at 520 nm which was attributed to the formation of excimers. Fluorescence has been used to monitor the interaction of cations with humic acids in solutions of different ionic strengths which shows promise for distinguishing between metat—humate complex formation and the coagulation of a colloid. The structures of the humic acids are discussed in terms of the structures possessed by lignites. 相似文献
15.
农药与腐植酸物质 总被引:4,自引:3,他引:1
河南省科学院化学研究所 《腐植酸》2001,(1):6-8
为了腐植酸事业的可持续发展,使腐植酸行业在二十一世纪对我国的经济发展作出更大的贡献,现将有关腐植酸物质与农药之间相互作用的一些情况介绍给大家,希望能对腐植酸事业的发展起到一点帮助和推动作用。 相似文献
16.
It has been found that humic acids in aqueous solution, as previously found with their sodium salts, behave as linear polyelectrolytes. A possible explanation in terms of intermolecular associative forces is suggested. 相似文献
18.
19.
20.
采用热重分析法(DTA-TGA)研究了腐殖酸的热分解过程及其动力学,分析其DTA-TGA曲线可得:热分解反应发生在284.65~417.16℃; 用红外光谱(FT-IR)、核磁氢谱(1H NMR)、核磁碳谱(13C NMR)对腐殖酸结构进行表征,用Flynn-Wall-Ozawa(F-W-O)法、Kissinger法及Šatava-Šesták法计算出腐殖酸热分解反应的表观活化能为210.83 kJ·mol-1,指前因子对数为17.55;确定了其热分解反应的级数和动力学参数,且热分解反应机理为二级反应;腐殖酸在氮气氛围下维持1min寿命的最高使用温度为278℃;同时,计算出腐殖酸样品热力学参数焓变、熵变及摩尔自由能变分别为67.99 kJ·mol-1、-164.83 J·(mol·K)-1 和176.36 kJ·mol-1。 相似文献